In the operation of machinery there is a continual raising of performance standards of lubricating compositions therefor with an objective of extending the life of the lubricating composition and/or improving its performance under severe operating conditions. One of the areas under particular scrutiny is in the area of the lubrication of gears, gear trains, bearings and the like, particularly the gear mechanisms in the differential of automobiles. One of the principal targets for improvement is the anticorrosive properties of the lubricating oil since many of the other additives performing antioxidant, VI, detergent dispersancy, load carrying and lubricity functions are often corrosive in themselves and/or break down during use into corrosive substances which result in severe corrosive attack of the lubricated machinery surface, e.g., gear surfaces, which undesirably results in their premature replacement.